In Vitro Performance Assessment of a Bioprosthetic Individualized Aortic Valve Prosthesis for Infants and Toddlers

This study evaluated the hydrodynamic performance of a handmade bioprosthetic aortic heart valve substitute intended for infants and toddlers. This valve was prepared using neutralized animal tissue and consequently tested in a pre-established pulse duplicator. Valve kinematics were characterized by an in-house developed image analysis algorithm. Analysis results provide a full map of valve's response including mean pressure differential, regurgitation, as well as orifice area during normotensive, hypotensive, and hypertensive conditions. The objective valve prosthesis was also compared with a commercially available pulmonary conduit along with an in-house built polyurethane valve. As growth is very rapid on target group's age, the investigation was further expanded to evaluate valve's response upon expansion (as in growth) of the aortic annulus. The latter was achieved by a novel scheme that uses vacuum conditions on a flexible silicone mock annulus, providing a diameter growth with highly biomimetic characteristics. The results demonstrated that the objective valve had good responsiveness, following norm's requirements in all tested conditions, with marginal deviation on regurgitation, while satisfactory responsiveness was evaluated in expanded (growth) state, too, representing 2 years of aging. Nevertheless, the alternative tested valves struggled to reach the requirements, while the potential on accommodation of growth appears limited particularly for rigid, stented valves.